mpd/doc/protocol.xml
Max Kellermann a3fd74d0dc doc: converted doc/COMMANDS to DocBook
The goal is to have one structured document which is the authoritative
protocol specification.  The documentation which currently resides in
the wiki will be merged.
2008-11-19 21:16:19 +01:00

1065 lines
34 KiB
XML

<?xml version='1.0' encoding="utf-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"docbook/dtd/xml/4.2/docbookx.dtd">
<book>
<title>The Music Player Daemon protocol</title>
<chapter>
<title>General protocol syntax</title>
<section>
<title>Requests</title>
<para>
If arguments contain spaces, they should be surrounded by double quotation
marks.
</para>
<cmdsynopsis>
<command>COMMAND</command>
<arg rep="Repeat"><replaceable>ARG</replaceable></arg>
</cmdsynopsis>
<para>
All data between the client and server is encoded in
UTF-8. (Note, that in UTF-8 all standard ansi characters,
0-127, are the same as a standard ansi encoding. Also, no
ansi character appears in any multi-byte characters. So, you
can use standard C functions like strlen, and strcpy just fine
with UTF-8 encoded strings. For example: "OK\n" encoded in
UTF-8 is simply "OK\n". For more information on UTF=8:
http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8)
</para>
</section>
<section>
<title>Responses</title>
<para>
A command returns "OK\n" on completion or "ACK some error\n" on failure.
These denote the end of command execution.
</para>
</section>
<section>
<title>Command lists</title>
<para>
To facilitate faster adding of files, etc, you can pass a list
of commands all at once using a command list. The command
list beings with <command>command_list_begin</command> or
<command>command_list_ok_begin</command> and ends with
<command>command_list_end</command>.
</para>
<para>
It does not execute any commands until the list has ended. The return
value is whatever the return for a list of commands is. On success
for all commands, OK is returned. If a command fails, no more commands
are executed and the appropriate ACK error is returned. If
"command_list_ok_begin is used", "list_OK\n" is returned for each
successful command executed in the command list.
</para>
</section>
</chapter>
<chapter>
<title>Command reference</title>
<note>
<para>
For manipulating playlists and playing, there are two sets of commands. One
set uses the song id of a song in the playlist, while another set uses the
playlist position of the song. The commands using song id's should be used
instead of the commands that manipulate and control playback based on playlist
position. Using song id's is a safer method when multiple clients are
interacting with MPD.
</para>
</note>
<section>
<title>Querying MPD's status</title>
<variablelist>
<varlistentry id="command_clearerror">
<term>
<cmdsynopsis>
<command>clearerror</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Clear the current error message in status (this is also
accomplished by any command that starts playback).
</para>
</listitem>
</varlistentry>
<varlistentry id="command_currentsong">
<term>
<cmdsynopsis>
<command>currentsong</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays the song info of current song (same song that
is identified in status).
</para>
</listitem>
</varlistentry>
<varlistentry id="command_idle">
<term>
<cmdsynopsis>
<command>idle</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Waits until there is a noteworthy change in one or more of
MPD's subsystems. As soon as there is one, it lists all
changed systems in a line in the format "changed: SUBSYSTEM",
where SUBSYSTEM is one of the following:
</para>
<itemizedlist>
<listitem>
<para>
<returnvalue>database</returnvalue>: the song database
has been updated
</para>
</listitem>
<listitem>
<para>
<returnvalue>stored_playlist</returnvalue>: a stored
playlist has been modified, renamed, created or
deleted
</para>
</listitem>
<listitem>
<para>
<returnvalue>playlist</returnvalue>: the current
playlist has been modified
</para>
</listitem>
<listitem>
<para>
<returnvalue>player</returnvalue>: the player has been
started, stopped or seeked
</para>
</listitem>
<listitem>
<para>
<returnvalue>mixer</returnvalue>: the volume has been
changed
</para>
</listitem>
<listitem>
<para>
<returnvalue>output</returnvalue>: an audio output has
been enabled or disabled
</para>
</listitem>
<listitem>
<para>
<returnvalue>options</returnvalue>: options like
"repeat", "random", "crossfade"
</para>
</listitem>
</itemizedlist>
<para>
While a client waits for <command>idle</command>
results, the server disables timeouts, allowing a client
to wait for events as long as mpd runs. The
<command>idle</command> command can be canceled by
sending the command <command>noidle</command> (no other
commands are allowed). MPD will then leave
<command>idle</command> mode and print results
immediately; might be empty at this time.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_status">
<term>
<cmdsynopsis>
<command>status</command>
</cmdsynopsis>
</term>
<listitem>
<para>
reports current status of player, and volume level.
</para>
<variablelist>
<varlistentry>
<term>volume</term>
<listitem>
<para>0-100</para>
</listitem>
</varlistentry>
<varlistentry>
<term>repeat</term>
<listitem>
<para>0 or 1</para>
</listitem>
</varlistentry>
<varlistentry>
<term>playlist</term>
<listitem>
<para>
31-bit unsigned integer, the playlist version
number
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>playlistlength</term>
<listitem>
<para>
integer, the length of the playlist
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>state</term>
<listitem>
<para>
"play", "stop", or "pause"
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>song</term>
<listitem>
<para>
current song stopped on or playing, playlist song
number
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>songid</term>
<listitem>
<para>
current song stopped on or playing, playlist
songid
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>time</term>
<listitem>
<para>
elapsed:total (of current playing/paused song)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>bitrate</term>
<listitem>
<para>
instantaneous bitrate in kbps
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>xfade</term>
<listitem>
<para>
crossfade in seconds
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>audio</term>
<listitem>
<para>
sampleRate:bits:channels
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>updatings_db</term>
<listitem>
<para>
job id
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>error</term>
<listitem>
<para>
if there is an error, returns message here
</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</varlistentry>
<varlistentry id="command_stats">
<term>
<cmdsynopsis>
<command>stats</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Display statistics.
</para>
<itemizedlist>
<listitem>
<para>
<varname>artists</varname>: number of artists
</para>
</listitem>
<listitem>
<para>
<varname>songs</varname>: number of albums
</para>
</listitem>
<listitem>
<para>
<varname>uptime</varname>: daemon uptime in seconds
</para>
</listitem>
<listitem>
<para>
<varname>db_playtime</varname>: sum of all song
times in db
</para>
</listitem>
<listitem>
<para>
<varname>db_update</varname>: last db update in UNIX
time
</para>
</listitem>
<listitem>
<para>
<varname>playtime</varname>: time length of music played
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Playback options</title>
<variablelist>
<varlistentry id="command_crossfade">
<term>
<cmdsynopsis>
<command>crossfade</command>
<arg choice="req"><replaceable>SECONDS</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Sets crossfading between songs.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_random">
<term>
<cmdsynopsis>
<command>random</command>
<arg choice="req"><replaceable>STATE</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Set random state to <varname>STATE</varname>, should
be 0 or 1.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_repeat">
<term>
<cmdsynopsis>
<command>repeat</command>
<arg choice="req"><replaceable>STATE</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Set repeat state to <varname>STATE</varname>,
<varname>STATE</varname> should be 0 or 1.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_setvol">
<term>
<cmdsynopsis>
<command>setvol</command>
<arg choice="req"><replaceable>VOL</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Set volume to <varname>VOL</varname>, the range of
volume is 0-100.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_volume">
<term>
<cmdsynopsis>
<command>volume</command>
<arg choice="req"><replaceable>CHANGE</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Change volume by amount <varname>CHANGE</varname>.
</para>
<note>
<para>
<command>volume</command> is deprecated, use
<command>setvol</command> instead.
</para>
</note>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Controlling playback</title>
<variablelist>
<varlistentry id="command_play">
<term>
<cmdsynopsis>
<command>play</command>
<arg><replaceable>SONGPOS</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Begin playing playlist at song number
<varname>SONGPOS</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_playid">
<term>
<cmdsynopsis>
<command>playid</command>
<arg><replaceable>SONGID</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Begin playing playlist at song
<varname>SONGID</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_next">
<term>
<cmdsynopsis>
<command>next</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Plays next song in playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_previous">
<term>
<cmdsynopsis>
<command>previous</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Plays previous song in playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_pause">
<term>
<cmdsynopsis>
<command>pause</command>
<arg choice="req"><replaceable>PAUSE</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Toggle pause/resume playing. <varname>PAUSE</varname> is 0 or 1.
</para>
<note>
<para>
Use of pause command w/o the _pause_ argument is
deprecated.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry id="command_seek">
<term>
<cmdsynopsis>
<command>seek</command>
<arg choice="req"><replaceable>SONGPOS</replaceable></arg>
<arg choice="req"><replaceable>TIME</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Seeks to the position <varname>TIME</varname> (in
seconds) of entry <varname>SONGPOS</varname> in the
playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_seekid">
<term>
<cmdsynopsis>
<command>seekid</command>
<arg choice="req"><replaceable>SONGID</replaceable></arg>
<arg choice="req"><replaceable>TIME</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Seeks to the position <varname>TIME</varname> (in
seconds) of song <varname>SONGID</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_stop">
<term>
<cmdsynopsis>
<command>stop</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Stop playing.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>The current playlist</title>
<variablelist>
<varlistentry id="command_add">
<term>
<cmdsynopsis>
<command>add</command>
<arg choice="req"><replaceable>URI</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Add the file <varname>URI</varname> to the playlist
(directories add recursively).
<varname>URI</varname> can also be a single file.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_addid">
<term>
<cmdsynopsis>
<command>addid</command>
<arg choice="req"><replaceable>URI</replaceable></arg>
<arg><replaceable>POSITION</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Adds a song to the playlist (non-recursive) and returns the song id.
</para>
<para>
<varname>URI</varname> is always a single file or
URL. <varname>POSITION</varname> is optional, a
negative number means it is relative to the currently
playing song in the playlist (if there is one).
example:
</para>
<screen>
addid "foo.mp3"
Id: 999
OK
</screen>
</listitem>
</varlistentry>
<varlistentry id="command_clear">
<term>
<cmdsynopsis>
<command>clear</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Clears the current playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_delete">
<term>
<cmdsynopsis>
<command>delete</command>
<arg choice="req"><replaceable>SONGPOS</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Deletes a song from the playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_deleteid">
<term>
<cmdsynopsis>
<command>deleteid</command>
<arg choice="req"><replaceable>SONGID</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Delete song <varname>SONGID</varname> from playlist
</para>
</listitem>
</varlistentry>
<varlistentry id="command_move">
<term>
<cmdsynopsis>
<command>move</command>
<arg choice="req"><replaceable>FROM</replaceable></arg>
<arg choice="req"><replaceable>TO</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Move song at <varname>FROM</varname> to
<varname>TO</varname> in the playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_moveid">
<term>
<cmdsynopsis>
<command>moveid</command>
<arg choice="req"><replaceable>FROM</replaceable></arg>
<arg choice="req"><replaceable>TO</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Move song with <varname>FROM</varname> to
<varname>TO</varname> (both song ids) in the
playlist. If <varname>TO</varname> is negative, it
is relative to the current song in the playlist (if
there is one).
</para>
</listitem>
</varlistentry>
<varlistentry id="command_playlist">
<term>
<cmdsynopsis>
<command>playlist</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays the current playlist.
</para>
<note>
<para>
Do not use this, instead use <command>playlistinfo</command>.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry id="command_playlistid">
<term>
<cmdsynopsis>
<command>playlistid</command>
<arg choice="req"><replaceable>SONGID</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays list of songs in the playlist.
<varname>SONGID</varname> is optional and specifies a
single song to display info for.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_playlistinfo">
<term>
<cmdsynopsis>
<command>playlistinfo</command>
<arg><replaceable>SONGPOS</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays list of songs in the playlist.
<varname>SONGPOS</varname> is optional and specifies
a single song to display info for.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_plchanges">
<term>
<cmdsynopsis>
<command>plchanges</command>
<arg choice="req"><replaceable>VERSION</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays changed songs currently in the playlist since
<varname>VERSION</varname>.
</para>
<para>
To detect songs that were deleted at the end of the
playlist, use playlistlength returned by status command.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_plchangesposid">
<term>
<cmdsynopsis>
<command>plchangesposid</command>
<arg choice="req"><replaceable>VERSION</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Displays changed songs currently in the playlist since
<varname>VERSION</varname>. This function only
returns the position and the id of the changed song, not
the complete metadata. This is more bandwidth efficient.
</para>
<para>
To detect songs that were deleted at the end of the
playlist, use playlistlength returned by status command.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_shuffle">
<term>
<cmdsynopsis>
<command>shuffle</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Shuffles the current playlist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_swap">
<term>
<cmdsynopsis>
<command>swap</command>
<arg choice="req"><replaceable>SONG1</replaceable></arg>
<arg choice="req"><replaceable>SONG2</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Swap positions of <varname>SONG1</varname> and
<varname>SONG2</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_swapid">
<term>
<cmdsynopsis>
<command>swapid</command>
<arg choice="req"><replaceable>SONG1</replaceable></arg>
<arg choice="req"><replaceable>SONG2</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Swap positions of of songs of
<varname>SONG1</varname> and
<varname>SONG2</varname> (both song ids).
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Stored playlists</title>
<variablelist>
<varlistentry id="command_load">
<term>
<cmdsynopsis>
<command>load</command>
<arg choice="req"><replaceable>NAME</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Loads the playlist <filename>NAME.m3u</filename> from
the playlist directory.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_listplaylists">
<term>
<cmdsynopsis>
<command>listplaylists</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Prints a list of the playlist directory.
</para>
<para>
After each playlist name, the server sends its last
modification time as attribute "Last-Modified" in ISO
8601 format. To avoid problems due to clock differences
between clients and the server, clients should not
compare this value with their local clock.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_rm">
<term>
<cmdsynopsis>
<command>rm</command>
<arg choice="req"><replaceable>NAME</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Removes the playlist <filename>NAME.m3u</filename> from
the playlist directory.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_save">
<term>
<cmdsynopsis>
<command>save</command>
<arg choice="req"><replaceable>NAME</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Saves the current playlist to
<filename>NAME.m3u</filename> in the playlist directory.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>The music database</title>
<variablelist>
<varlistentry id="command_find">
<term>
<cmdsynopsis>
<command>find</command>
<arg choice="req"><replaceable>TYPE</replaceable></arg>
<arg choice="req"><replaceable>WHAT</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
finds songs in the db that are exactly
<varname>WHAT</varname>. <varname>TYPE</varname> should
be <parameter>album</parameter>,
<parameter>artist</parameter>, or
<parameter>title</parameter>. <varname>WHAT</varname>
is what to find.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_list">
<term>
<cmdsynopsis>
<command>list</command>
<arg choice="req"><replaceable>TYPE</replaceable></arg>
<arg><replaceable>ARTIST</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
List all tags of the specified type.
<varname>TYPE</varname> should be "album" or "artist".
</para>
<para>
<varname>ARTIST</varname> is an optional parameter
when type is album, this specifies to list albums by a
artist.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_listall">
<term>
<cmdsynopsis>
<command>listall</command>
<arg><replaceable>URI</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Lists all songs and directories in
<varname>URI</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_listallinfo">
<term>
<cmdsynopsis>
<command>listallinfo</command>
<arg><replaceable>URI</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Same as <command>listall</command>, except it also
returns metadata info in the same format as
<command>lsinfo</command>.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_lsinfo">
<term>
<cmdsynopsis>
<command>lsinfo</command>
<arg><replaceable>URI</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
List contents of directory <varname>URI</varname>.
</para>
<para>
When listing the root directory, this currently returns
the list of stored playlists. This behavior is
deprecated; use "listplaylists" instead.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_search">
<term>
<cmdsynopsis>
<command>search</command>
<arg choice="req"><replaceable>TYPE</replaceable></arg>
<arg choice="req"><replaceable>WHAT</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Searches for any song that contain
<varname>WHAT</varname>. <varname>TYPE</varname> can be
<parameter>title</parameter>,
<parameter>artist</parameter>,
<parameter>album</parameter> or
<parameter>filename</parameter>. Search is not case
sensitive.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_update">
<term>
<cmdsynopsis>
<command>update</command>
<arg><replaceable>URI</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
Updates the music database.
</para>
<para>
<varname>URI</varname> is a particular directory or
song/file to update.
</para>
<para>
Prints "updating_db: JOBID" where
<varname>JOBID</varname> is the job id requested for
your update, and is displayed in status, while the
requested update is happening.
</para>
<para>
To update a number of paths/songs at once, use
command_list, it will be much more faster/efficient.
Also, if you use a command_list for updating, only one
<command>update</command> job id will be returned per
sequence of updates.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Connection settings</title>
<variablelist>
<varlistentry id="command_close">
<term>
<cmdsynopsis>
<command>close</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Closes the connection to MPD.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_kill">
<term>
<cmdsynopsis>
<command>kill</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Kill MPD.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_password">
<term>
<cmdsynopsis>
<command>password</command>
<arg choice="req"><replaceable>PASSWORD</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
<para>
This is used for authentication with the server.
<varname>PASSWORD</varname> is simply the plaintext
password.
</para>
</listitem>
</varlistentry>
<varlistentry id="command_ping">
<term>
<cmdsynopsis>
<command>ping</command>
</cmdsynopsis>
</term>
<listitem>
<para>
Does nothing but return "OK".
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</chapter>
</book>